Re: ASSM vs. non-ASSM
From: ddf <oratune_at_msn.com>
Date: Wed, 25 Jan 2012 13:19:09 -0800 (PST)
Message-ID: <05410deb-770a-4c2b-8bd7-5cd2fbb1fb1e_at_h12g2000yqg.googlegroups.com>
On Jan 25, 1:21 pm, "Gerard H. Pille" <g..._at_skynet.be> wrote:
> Mladen Gogala wrote:
> > I am engaged in a discussion about moving from 10g --> 11g. The
> > tablespaces in this particular 10G are all created with the manual
> > segment space management. I am reading the blogs and am aware of all the
> > troubles that ASSM can cause, ranging from wasting space to problems with
> > the free lists and even some spurious corruption issues.
> > However, Oracle made ASSM default in version 10g, and this project is
> > about upgrading a large production DB. What are the opinions here? Does
> > it make sense to go with manual SSM or should I go with ASSM?
>
> We have a couple of tables in which there are continuous inserts and deletes, at a dreadful
> rate, and we have to rebuild the indexes every week, to keep size and performance in check.
>
> Could not fall back to MSSM, because system is also ASSM, I seem to remember.
Date: Wed, 25 Jan 2012 13:19:09 -0800 (PST)
Message-ID: <05410deb-770a-4c2b-8bd7-5cd2fbb1fb1e_at_h12g2000yqg.googlegroups.com>
On Jan 25, 1:21 pm, "Gerard H. Pille" <g..._at_skynet.be> wrote:
> Mladen Gogala wrote:
> > I am engaged in a discussion about moving from 10g --> 11g. The
> > tablespaces in this particular 10G are all created with the manual
> > segment space management. I am reading the blogs and am aware of all the
> > troubles that ASSM can cause, ranging from wasting space to problems with
> > the free lists and even some spurious corruption issues.
> > However, Oracle made ASSM default in version 10g, and this project is
> > about upgrading a large production DB. What are the opinions here? Does
> > it make sense to go with manual SSM or should I go with ASSM?
>
> We have a couple of tables in which there are continuous inserts and deletes, at a dreadful
> rate, and we have to rebuild the indexes every week, to keep size and performance in check.
>
> Could not fall back to MSSM, because system is also ASSM, I seem to remember.
Richard Foote discussed index growth in a blog post a couple of weeks ago and through some testing of my own I discovered a reverse-key index could help keep the index size down:
http://oratips-ddf.blogspot.com/2012/01/my-how-youve-grown.html
It might help in your situation.
David Fitzjarrell Received on Wed Jan 25 2012 - 15:19:09 CST